[Index] Respect "IndexFunctionLocals" option for type loc.

Summary:
Previously, clang index ignored local symbols defined in the function body even
IndexFunctionLocals is true.

Reviewers: sammccall

Reviewed By: sammccall

Subscribers: ilya-biryukov, ioeric, arphaman, kadircet, cfe-commits

Differential Revision: https://reviews.llvm.org/D52877

llvm-svn: 343767